1. Field of the Invention
The present invention relates to a photographic camera of the self-developing type having an electronic flash, in general, and to such a camera having means for reducing the overall cycle time of such a camera, in particular.
2. Description of the Prior Art
Automatic photographic cameras of the self-developing type such as those sold by Polaroid Corporation of Cambridge, Mass., under its registered trademark "Impulse" are well known in the art. These cameras are intended to be used with film cassettes containing a plurality of self-developing film units together with a battery which supplies electrical energy for the operation of certain camera systems whose functions, in part, are to expose and process a film unit. These cameras may, for example, include an exposure control system, a motor powered film transport system for transporting and processing an exposed film unit and electronic logic circuits that provide a sequence control of such camera systems. In addition, these cameras are adapted for use with an electronic flash that is powered from the same film cassette battery in a manner similar to that described in U.S. Pat. No. 4,074,295 to R. C. Kee or in U.S. Pat. No. 4,231,645 to C. W. Davis, et al, both in common assignment herewith.
Heretofore, the simultaneous charging of an electronic flash in a self-developing camera and the operation of an electrical subsystem that causes a heavy power drain of the camera's battery, such as the operation of the motor that powers the film unit transport system mentioned above, was avoided. Such simultaneous charging and motor operation would consume large amounts of power and thereby may reduce the battery's output voltage below a level where it could properly drive the motor for film processing purposes, if the power consumption continued for an extended period of time. Therefore, the operation of the film transport and processing motor and the charging of the electronic flash was sequentially timed so as not to occur simultaneously. This sequential type of electronic flash charging and motor control is fully described in U.S. Pat. No. 3,846,812 to C. H. Biber, in common assignment herewith. In the camera described in this just-mentioned patent, once an exposed film unit has been transported for processing and ejected from the camera, the electronic flash is sequenced to charge in readiness for the next succeeding photographic exposure operation. During the time that the motor is being operated for film transportation and processing, charging of the electronic flash is inhibited. In the above-noted "Impulse" camera, for example, electronic flash charging is inhibited for almost two seconds, which is approximately one-half the total time required to fully charge the electronic flash. The length of time that the charging of the electronic flash is inhibited is an additional length of time that a camera operator must wait before initiating the next camera cycle, a length of time that may interfere with the camera operator's ability to rapidly photograph the next scene.